1. Field of the Invention
The invention relates to a shift register, and more particularly to a shift register applied to a gate driver of a display panel.
2. Description of the Related Art
Generally, in an active matrix display device, a gate driver which is used to drive a pixel array comprises a shift register. The shift register comprises a plurality of shift register units, and each shift register unit generates an output signal at an output node to the pixel array. Each shift register unit comprises a driving transistor coupled to an output node. As found in some prior arts, the voltage applied to the gate turns on the driving transistor for driving the output signal. The resistance of driving transistor has to be smaller for better driving capability for gate driver to drive heavier capacitive loading. When the shift register of these prior arts is applied to a gate driver of an active matrix display device, the size of the driving transistor of each shift register unit has to become larger to enhance the driving capability of the driving transistor, unless increasing the voltage applied to the gate of driving transistor. Thus, the area of the gate driver also becomes larger, which disadvantageously increase the size of the ledge of the active matrix display device.
Thus, it is desired to provide a shift register which has enhanced driving capability for output signals and occupy less area, with other than the method of increasing the size of driving transistor.